Input Phase Failure

What does -PHF mean?

This fault indicates a loss or significant imbalance of one or more input phases to the drive controller. Common causes include blown line fuses, loose connections, or an issue with the utility supply. Using a 3-phase drive on a single-phase supply without proper configuration can also trigger this. Operating with missing phases can lead to motor and drive damage due to unbalanced currents.

Complete Troubleshooting Guide

1. 1

   Inspect all input power fuses (L1, L2, L3) to the drive controller and replace any blown fuses after identifying the cause.

2. 2

   Using a multimeter, verify voltage on all three input phases to the drive controller and check for significant phase imbalance between phases.

3. 3

   Confirm that all input power connections are tight and secure at the drive terminals, main disconnect, and upstream distribution panel. Ensure the drive is supplied with proper 3-phase power if required by its model.